title: Degradative properties and cytocompatibility of a mixed-mode hydrogel containing oligo[poly(ethylene glycol)fumarate] and poly(ethylene glycol)dithiol.
abstract: Our laboratory is currently exploring synthetic oligo(poly(ethylene glycol)fumarate) (OPF)-based biomaterials as a means to deliver fibroblasts to promote regeneration of central/partial defects in tendons and ligaments. In order to further modulate the swelling and degradative characteristics of OPF-based hydrogels, OPF crosslinking via a radically initiated, mixed-mode reaction involving poly(ethylene glycol) (PEG)-diacrylate and PEG-dithiol was investigated. Results demonstrate that mixed-mode hydrogels containing OPF can be formed and that the presence of 20 wt.% PEG-dithiol increases swelling and decreases degradation time vs. 10 wt.% PEG-dithiol and non-thiol-containing hydrogels (20% thiol fold swelling 28.7+/-0.8; 10% thiol fold swelling 11.6+/-1.4; non-thiol 8.7+/-0.2; 20% thiol-containing hydrogels degrade within 15 days in vitro). After encapsulation, tendon/ligament fibroblasts remained largely viable over 8 days of static culture. While the presence of PEG-dithiol did not significantly affect cellularity or collagen production within the constructs over this time period, image analysis revealed that the 20% PEG-dithiol gels did appear to promote cell clustering, with greater values for aggregate area observed by day 8. These experiments suggest that mixed-mode OPF-based hydrogels may provide an interesting alternative as a cell carrier for engineering a variety of soft orthopedic tissues, particularly for applications when it is important to encourage cell-cell contact.
authors.affiliation: Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 313 Ferst Dr., Atlanta, GA 30332, USA. kelly.brink@bme.gatech.edu
authors.forename: Kelly S
authors.initials: KS
authors.lastname: Brink
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Yang
authors.forename: Johnna S
authors.initials: JS
authors.lastname: Temenoff
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D002417:Cattle; D002478:Cells, Cultured; D002850:Chromatography, Gel; D003094:Collagen / Q000378:metabolism; D020100:Hydrogels; D011091:Polyesters / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D023822:Tissue Engineering
chemical_list: D001672:Biocompatible Materials; D020100:Hydrogels; D011091:Polyesters; D013438:Sulfhydryl Compounds; C469550:oligo(poly(ethylene glycol)fumarate); C535242:poly(ethylene glycol)dithiol; D011092:Polyethylene Glycols; D003094:Collagen